[An Indicator of Treatment Quality in Ambulatory Care in Switzerland: Potential drug interaction in older people with polpharmacy in primary care].

Introduction: Background The Swiss Society of General Internal Medicine (SGAIM) has chosen the topic "Recognising drug interactions and preventing side effects" as a quality indicator in the primary care setting. Methodology Retrospectively, in a group practice of 6 general practitioners (GPs), all patients aged 65 and over who were prescribed ≥ 5 long-term medications were identified in the year 2022. These medications were systematically checked for interaction reports using the Compendium® software. Results The 226 patients were on average 77 years old and took an average of 7 different medications. In 188 (83.2 %) individuals with drug interaction signals, the severity of the drug interaction was classified as mild in 164 (87.3 %), moderate in 21 (11.1 %) and severe in 3 (1.6 %). Diuretics, antidiabetics and ACE-inhibitors/sartans were most frequently involved. In case of severe drug interaction reports, antidepressant agents and amiodarone were most frequently involved. In the multivariate analysis, no statistically significant associations were identified between the number of drug interaction reports and age, gender or type of residence. Conclusion In over 65-year-olds with polypharmacy (≥ 5 medications) in a GP setting, a software-supported systematic drug interaction check identified drug interactions of the prescribed medication in nine out of ten patients. The vast majority of drug interaction reports were minor and not clinically relevant. The number of drug interactions as an indicator of quality of care is limited, as patient-specific information other than their medication regimens is not taken into account. GPs' classification in the clinical context and the context and the assessment of the benefits and risks of (poly-)medication is indispensable.